I can do this using Radio Shack's promotion of trading in your previous iPhone 3gs for an iPhone 4 and get it for at least as $20. I know I have to restore it before doing so so let me get this right, I used Tiny Umbrella to saved the SHSH of iPhone 4.0. 4.01, and 4.1, and currently the iPhone is at 4.0.1 so if I restore it it will restore it to the current version. So if I get the iPhone 4, am i still able to JB it?